Ominously, this article mixes hard facts with estimates and opinions, without emphasizing the differences between these sources of information. In paragraph 3, official government statistics are given on the number of grow sites and plants eradicated by the government. But the author pivots ambiguously from these facts about grow sites to speculation about the pollution caused by this activity. This interpolation between statistics and speculation happens several more times throughout the article. I am certainly not claiming that Ms. Cone is making up facts, or that marijuana production does not pollute. But this article gives the improper impression that this phenomenon is well-documented and quantified. In reality, it seems that we are in the early stages of investigating how this activity effects our national parks.